Exhaust gas post processing system

ABSTRACT

An exhaust gas post processing system may include an exhaust line for an exhaust gas exhausted from an engine to pass, a gasoline particulate filter that is disposed on the exhaust line to filter harmful materials included in the exhaust gas, a bypass line that is disposed on the exhaust line such that the exhaust gas bypasses the gasoline particle filter, and a control portion that detects a driving condition of the engine and makes the exhaust gas pass the gasoline particulate filter or makes the exhaust gas bypasses the gasoline particulate filter according to the detected driving condition.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent Application Number 10-2010-0115634 filed in the Korean Intellectual Property Office on Nov. 19, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to an exhaust gas post processing system that is equipped with a gasoline particle filter (GPF) that filters particle materials included in exhaust gas of an engine.

2. Description of Related Art

Generally, a gasoline direct injection (GDI) engine, such as a diesel engine, makes air flow into a cylinder and directly injects fuel into the cylinder, and some amount of particle materials is exhausted with the exhaust gas.

A gasoline particle filter (GPF) is mounted so as to reduce the particle materials. In a case that the gasoline particle filter is disposed on the exhaust line, back pressure of the exhaust line is increased, output is decreased, and fuel consumption is increased.

The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention have been made in an effort to provide an exhaust gas post processing system having advantages of reducing fuel consumption increment and output decrement that are induced by a gasoline particle filter that filters particle materials included in the exhaust gas of the gasoline direct injection engine.

The exhaust gas post processing system may include an exhaust line for exhaust gas exhausted from an engine to pass, a gasoline particulate filter that is disposed on the exhaust line to filter harmful materials included in the exhaust gas, a bypass line that is disposed on the exhaust line such that the exhaust gas bypasses the gasoline particle filter, and a control portion that detects a driving condition of the engine and makes the exhaust gas pass the gasoline particulate filter or makes the exhaust gas bypass the gasoline particulate filter according to the detected driving condition.

A main valve may be disposed at an upstream side of the gasoline particle filter to selectively cut off the exhaust gas flowing into the gasoline particle filter, and the control portion closes the main valve such that the exhaust gas passes the bypass line.

A bypass valve may be disposed on the bypass line to selectively cut off the exhaust gas passing the bypass line.

The control portion may make the exhaust gas pass the gasoline particulate filter if the heating logic is performed so as to heat the gasoline particle filter.

The control portion may detect a rotation speed of the engine and makes the exhaust as pass the gasoline particle filter if the rotation speed exceeds a predetermined value.

The control portion may detect a coolant temperature of the engine and makes the exhaust gas pass the gasoline particle filter if the coolant temperature is lower than a predetermined value.

The control portion may detect an oil temperature of the engine and makes the exhaust gas pass the gasoline particle filter if the oil temperature is lower than a predetermined value.

The control portion may detect a speed of a vehicle and makes the exhaust gas pass the gasoline particle filter if the speed is higher than a predetermined value.

The control portion may make the exhaust gas pass the bypass line rather than the gasoline particle filter, if a heating logic for heating the gasoline particle filter is not performed, if a rotation speed of the engine is lower than a predetermined value, if a coolant temperature of the engine is higher than a predetermined value, if an oil temperature of the engine is higher than a predetermined value, and if a speed of a vehicle is lower than a predetermined value.

As stated above, the exhaust gas is induced to selectively pass a gasoline particle filter according to a driving condition of the engine such that the fuel consumption is reduced and the output deterioration is reduced in an exhaust gas post processing system according to the present invention.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an exemplary exhaust gas post processing system according to the present invention.

FIG. 2 is a flowchart for controlling an exemplary exhaust gas post processing system according to the present invention.

FIG. 3 is a graph showing the particle amount included in the exhaust gas in an exemplary exhaust gas post processing system according to the present invention.

FIG. 4 is a graph showing a relation of a driving condition of an engine and a gasoline particle filter (GPF) in an exemplary exhaust gas post processing system according to the present invention.

FIG. 5 is a graph showing a relation of a fuel consumption amount and a gasoline particle filter (GPF) in an exemplary exhaust gas post processing system according to the present invention.

FIG. 6 is a graph showing a relation of a coolant temperature and the particle amount included in the exhaust gas in an exemplary exhaust gas post processing system according to the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

Referring to FIG. 1, an exemplary exhaust gas post processing system may include an engine 100, an exhaust line 110, a gasoline particle filter (GPF) 130, a bypass line 140, a main valve 120, a bypass valve 150, and a control portion 160.

Exhaust gas exhausted from the engine 100 passes the exhaust line 110, and the gasoline particle filter 130 filters particle materials included in the exhaust gas. The engine 100 is of a gasoline direct injection type and directly injects fuel into a cylinder.

A bypass line 140 is disposed to bypass the gasoline particle filter 130 on the exhaust line 110 and the bypass valve 150 may be disposed on the bypass line 140. The bypass line 140 is diverged from the exhaust line of the upstream side of the GPF 130 to join the exhaust line of the downstream side of the GPF 130

Further, the main valve 120 is disposed on the exhaust line 110 of the upstream side of the gasoline particle filter 130 so as to selectively cut off the exhaust gas flowing through the gasoline particle filter 130.

Accordingly, if the main valve 120 is closed and the bypass valve 150 is opened by the control portion 160, the exhaust gas passing the exhaust line 110 flows through the bypass line 140 rather than the gasoline particle filter 130 of the exhaust line.

Further, if the main valve 120 is opened and the bypass valve 150 is closed by the control portion 160, the exhaust gas flowing through the exhaust line 110 passes the gasoline particle filter 130 rather than the bypass line 140.

Particularly, in a case that the exhaust gas passes the gasoline particle filter 130, there are problems that the pressure of the exhaust gas is increased, the output of the engine is deteriorated, and the fuel consumption is increased.

The control portion 160 selectively makes the exhaust gas pass the bypass line 140 according to a driving condition of the engine in an exemplary embodiment of the present invention so as to prevent the fuel consumption from being increased and the output of the engine from being deteriorated.

The control portion 160 executes a heating logic for heating the gasoline particle filter 130 to effectively purify the exhaust gas in a cold state of the engine 100 and detects a rotation speed, a coolant temperature, and an oil temperature of the engine 100.

Referring to FIG. 2, a control is started in a S200 and an engine 100 is started in a S210.

Whether a heating logic for heating an oxidation catalyst or a GPF is performed or not is determined in a S220. The catalyst includes a gasoline particle filter and may include all catalysts disposed on the exhaust line. If the logic for heating the catalyst is performed in the S220, the control portion makes the exhaust gas pass the gasoline particle filter (130, GPF) in a S280.

Whether a rotation speed (RPM) of the engine 100 is higher than a predetermined value is determined in a S230. If the RPM exceeds the predetermined value, the control portion makes the exhaust gas pass the gasoline particle filter 130 in a S280.

Whether a coolant temperature of the engine 100 is lower than a predetermined value is determined in a S240. If the coolant temperature is lower than the predetermined value, the control portion makes the exhaust gas pass the gasoline particle filter in a S280.

Whether an oil temperature of the engine 100 is less than a predetermined value is determined in a S250. If the oil temperature is lower than a predetermined value, the control portion makes the exhaust gas pas the gasoline particle filter 130 in a S280.

Whether a vehicle speed is higher than a predetermined value is determined in a S260. If the vehicle speed exceeds the predetermined value, the exhaust gas passes the gasoline particle filter 130 in a S280.

If the heating logic for the catalyst is not performed, the rotation speed of the engine 100 is lower than the predetermined value, the coolant temperature is higher than a predetermined value, the oil temperature is higher than the predetermined value, and the vehicle speed is lower than the predetermined value in the S220, S230, S240, S250, and S260, the control portion makes the exhaust gas pass the bypass line 140 in a S270 such that the exhaust gas does not pass the gasoline particle filter 130.

Accordingly, the back pressure of the exhaust gas is decreased such that the output of the engine is not deteriorated and the fuel consumption is reduced.

Referring to FIG. 3, a horizontal axis denotes a time, a vertical axis denotes the amount of particle materials (PM) included in the exhaust gas, a coolant temperature, an oil temperature, a catalyst (gasoline particle filter) temperature, and an exhaust temperature.

As shown, the amount of the particle materials included in the exhaust gas is related to the coolant temperature, the oil temperature, the catalyst temperature, and the exhaust gas temperature. Particularly, the lower the coolant temperature is, the more the amount of the particle materials is, and the lower the oil temperature is, the more the amount of the particle materials.

And, the lower the temperatures of the catalyst and the exhaust gas are, the more the amount of the particle materials is. In addition, the rotation speed of the engine 100 is related to the vehicle speed, the higher the rotation speed and the vehicle speed are, the larger the amount of the particle materials is.

Referring to FIG. 4, a horizontal axis signifies a rotation speed of the engine 100 and a vertical axis signifies a power and a torque. A TWC denotes a three way catalytic converter, a GPF denotes a gasoline particle filter 130, a bare signifies that there is not a catalyst, and 2X and 3X signifies the amounts of catalysts.

As shown, if the exhaust gas passes the gasoline particulate filter 130 where the catalyst is coated, the output and torque of the engine 100 decrease.

Referring to FIG. 5, a horizontal axis shows a combination of a three way catalytic converter (TWC) and a gasoline particle filter (GPF) and a vertical axis signifies a unit fuel consumption amount. Here, the bare signifies that there is no catalyst and the 2X and the 3X show the amounts of the catalyst.

As shown, as the gasoline particle filter 130 is applied or the catalyst amount is increased, the unit fuel consumption amount is increased.

Referring to FIG. 6, a horizontal axis denotes a time and a vertical axis denotes a coolant temperature and an amount of PM according to an injection condition of the fuel.

As shown, the amount of the particle materials included in the exhaust gas is differently distributed according to the coolant temperature and the fuel injection condition. Particularly, the lower the coolant temperature, the larger the amount of the particle material included in the exhaust gas.

For convenience in explanation and accurate definition in the appended claims, the term “lower” and other terms are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. An exhaust gas post processing system, comprising: an exhaust line for an exhaust gas exhausted from an engine to pass; a gasoline particulate filter that is disposed on the exhaust line to filter harmful materials included in the exhaust gas; a bypass line that is disposed on the exhaust line such that the exhaust gas bypasses the gasoline particle filter; and a control portion that detects a driving condition of the engine and makes the exhaust gas pass or bypass the gasoline particulate filter according to the detected driving condition.
 2. The exhaust gas post processing system of claim 1, wherein a main valve is disposed at an upstream side of the gasoline particle filter to selectively cut off the exhaust gas flowing into the gasoline particle filter, and the control portion closes the main valve such that the exhaust gas passes the bypass line.
 3. The exhaust gas post processing system of claim 1, wherein a bypass valve is disposed on the bypass line to selectively cut off the exhaust gas passing the bypass line.
 4. The exhaust gas post processing system of claim 2, wherein the control portion makes the exhaust gas pass the gasoline particulate filter if the heating logic is performed so as to heat the gasoline particle filter.
 5. The exhaust gas post processing system of claim 2, wherein the control portion detects a rotation speed of the engine and makes the exhaust gas pass the gasoline particle filter if the rotation speed exceeds a predetermined value.
 6. The exhaust gas post processing system of claim 2, wherein the control portion detects a coolant temperature of the engine and makes the exhaust gas pass the gasoline particle filter if the coolant temperature is lower than a predetermined value.
 7. The exhaust gas post processing system of claim 2, wherein the control portion detects an oil temperature of the engine and makes the exhaust gas pass the gasoline particle filter if the oil temperature is lower than a predetermined value.
 8. The exhaust gas post processing system of claim 2, wherein the control portion detects a speed of a vehicle and makes the exhaust gas pass the gasoline particle filter if the speed is higher than a predetermined value.
 9. The exhaust gas post processing system of claim 2, wherein the control portion may make the exhaust gas pass the bypass line rather than the gasoline particle filter, if a heating logic for heating the gasoline particle filter is not performed, if a rotation speed of the engine is lower than a predetermined value, if a coolant temperature of the engine is higher than a predetermined value, if an oil temperature of the engine is higher than a predetermined value, and if a speed of a vehicle is lower than a predetermined value. 